Normalize latex path

Hi,
  due to an unrelated bug report in maxima I found out that some packages 
install latex packages in /usr/share/texmf/tex/latex. Instead of using the 
prefix %{_datadir}/texmf we can use the canonical %_texmf defined by texlive.

Is there any objection to change the location to the canonical location?
Actually if you look into the spec file we are using a symbolic link. As far 
as I can see the change is harmless.

Probably the %postun and %posttrans sections can be simplified.

Best regards,